In the German patent publication DE-PS 29 05 770, there is disclosed a magazine retainer which is pivotally mounted in a milled-out notch in the stock of the weapon so as to pivot around a horizontal axis disposed transversely to the firing direction of the firearm. The magazine retainer is spring loaded and is provided with a nose portion which is engageable with a catch in the magazine in order to lock the magazine within the magazine chamber in the pistol stock. The magazine retainer extends outwardly on both sides of the pistol stock and is provided with actuation plates on both sides thereof so that the magazine retainer can be actuated by either right-handed or left-handed persons handling the firearm. The actuation plate is pressed forward by the thumb of the shooting hand to cause pivoting of the magazine retainer and to thus disengage the nose from the magazine catch so that the magazine is then free to fall downwardly out of the magazine chamber.
However, this known magazine retainer has the disadvantage that both actuation plates project outwardly beyond the lateral surfaces of the pistol. As a result, there is the ever present danger that the projecting actuation plate of the pistol may be inadvertently caught by the holster, for example, when the pistol is being taken from or put back into the holster. Further, because of the outwardly projecting actuation plates, an undesired release of the magazine can occur under various other circumstances independent of removal from or placing back the pistol in a holster.